Locomotive-boiler furnace.



No. 820,450. 7 PATENTED MAY 15, 1906. E. H. WADE & J. L. NICHOLSON. LOGOMOTIVE BOILER FURNACE.

APPLICATION FILED SEPT, 13, 1904.

3 SHEETSSHEET 1.

(TC/60km No. 820,450. PATENTED MAY 15, 1906. E. H. WADE & J. L. NICHOLSON. LOCOMOTIVE BOILER FURNACE.

APPLICATION FILED s PT,18 1904.

. E 3SHEETS-SHEBT 2. I

No. 820,450. PATENTED MAY 15, 1906.

I E. H. WADE & J. L. NICHOLSON. LOOOMOTIVE BOILER FURNACE.

APPLICATION FILED SEPT,13,1904.

3 SHEETS-SHEET 3 UNITED STATES PATENT orrron.

EVAN H. WADE AND JOHN L. NICHOLSON, OF CHICAGO, ILLINOIS,

ASSIGNORS TO AMERICAN LOCOMOTIVE EQUIPMENT 00., OF

CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS.

LOCOMOTIVE-BOILER FURNACE.

Specification of Letters lPatent.

Patented May 15, 1906.

T 0 all whom it may concern:

Be it known that we, EVAN H. WAD and JOHN L. NroHoLsoN, citizens of the United States, residing in Chicago, in the county of Cook and State of Illinois, have invented a certain new, useful, and Improved Locomotive-Boiler Furnace, of which the following is a specificatign. I

Our invention relates to locomotive-boilers and to improvements in the furnaces thereof.

The invention has further and special reference to improvements upon the furnace which is shown and described in Letters Patent No. 744,135, granted to E. H. Wade-J. L. Nicholson, and S. C. Smith, November 17, 1903. v

The object ofour invention is to improve combustion in locomotive boiler furnaces and in furnaces generally, and the particular object of our invention is to improve the construction and operation of the aforesaid patented furnace and add to the effectiveness thereof.

It is well known that locomotive boiler furnaces are deficient in grate area and that to secure the requisite evaporation of Water it is necessary to force their fires. This is done by a blast of steam created from the ex haust of the engines and said blast is so powerful that the draft throu h the furnacegrate is sufficient to disrupt tIie fire and uncover parts of the grate unless muchcare is exercised in firing the furnace. It isalso well known that the combustion in locomotive-boilers is very imperfect and that in efficiency locomotive-furnaces compare unfavorably with stationary-boiler furnaces.

Combustion proceeds upon a fixed. principle.

The inefficiency of locomotive-boiler furnaces is due to their peculiar form and disproportionate size, resulting in an inadequate supply and admixture of air to and with the combustible products. Our purpose is to take advanta e of the partial vacuum that is created in t e fire-box of a locomotive-boiler and cause or admit an inrush (if air above the grate to reduce such vacuum, and thereby prevent the disruption of the fire and also supplement the volume of air normally drawn throu h the grate. In brief, a distinct object of our invention is to provide a furnace that shall combine the principles and effects of both '11 draft and downdraft furnaces. The comp eteness to which combustion will progress in fuel is dependent upon the intimacy of admixture ,between the combustible products and oxygen from the atmosphere and upon whether or no oxygen is supplied in sufficient quantities to make proper combinations with all said products. We provide means to form within the furnaces a restricted throat or opening between the fire and combustion chambers and to maintain thereacross a barrier .of air which all the fuel elements and gases from the fire-chamber must penetrate in order to reach the combustion-chamber of the furnace, and, further, by the same means we provide for an adequate and vsufficient supply of air not only to the bottom of the fire upon the grate, but also to the upper surface of the body of the burning fuel, to insure intimate and complete combination of the rising gases With the admitted air. v

Specifically defined and as herein shown,

our invention consists in a boiler-furnace comprising a fire-box having a grate and divided into fire and combustion chambers by transverse arches between which is an opening or throat leadin from the fire-chamber into the combustion-c amber. The ends ofthe walls or arches which outline or define the throat of the furnace we provide with air-entrance openings or cavities and with deflectors or deflecting-surfaces that tend to cause the moving of air there admitted to descend uponthe fire on the grate. The construction is such that the two or more currents of air entering through said walls or arches together constitute a complete air barrier beneath and across the furnace-throat, through and with which supplied air the fuel-gases must pass and unite beforereaching the combustionchamber. Through recognitionof a true rinciple of admixing fuel-gases and air we have remedied the defects in earlier furnaces by so arranging the air ducts or passages of the furnace-dividing walls orarches that the currents or sheets of hot air entering therethroughwill because of their lower temperature, their velocity, and fixed direction fiow or fall toward and upon neath and also converge at a point below the throat of the furnace, thus providing for and the burning fuel bep view on the line E E of Fig. l.

maintainin a complete barrier of hot air beneath the rnace-throat and therefrom enriching-the fuel-gases and elements to the extent required for their complete combustion within and'above said throat. Our invention further consists in the combination of a furnace and its grate with transverse walls or arches separated by an opening or throat and which prevent the direct passage of the combustibles and products of combustion from the burning fuel to the boiler-fines and which'contain air-supplying ducts and deflectors through which air is drawn into the furnace, heated, and, so to speak, poured upon the surface of the burning fuel'to prevent excessive effects of vacuum within the furnace and insure the cornlete combustion of the fuel products rising omthe grate; and, further, our invention consists-in walls or arches havin the above characteristics and functions and which are self sustaining within the 'furnacein other words, such as may be employed with or without the arch-tubes which are found in many locomotive-boiler furnaces; and, further, our invention consists in various details of construction and in combinations of parts, all as hereinafter described, and. particularly pointed out in the claims.

The invention-will be more readily understood by reference to the accompanying drawings, forming a part of this specification, and in which Figure 1 is a longitudinal section of a boiler-furnace embodying our invention. Fig. 2 is a view of the rearend of a boiler, the furnace and the rear'arch therein being shown in dotted lines. Fig. 3 is a compound verti cal section of a boiler, one half of the view being on the line A A of Fig. 1 and the other half on the line B 3 of Pi l viewed in the direction of the arrows. "ig. i is a vertical section on the irregular line C C of Fig. 1 viewed in the opposite direction as shown by arrows. Fig. 5 1s vertical section on the line D D of 1. Fig. 6 is a sectional Fig. .7 is a horizontal section on the irregular line F F of Fig. 1 viewed "from beneath as indicated by arrows. Fig. 8 is an end view of the throat framing or outlinin bricks; and Fig. 9 is an end view of a pair 0 intermediate hollow or channeled bricks, several pairs of which areused in the front arch, while usually only a single pair is employed in the rear arch.

The boiler represented in the drawings is of a common locomotive t pe.

2 is the shell of the boiler, which contains the furnace, whereof 3 is the flue-sheet.

4 is the crown-sheet, 5 the rear end, and 6 6 the side sheets or walls. The rear end contains the door-o en-ing 7, and the bottom of the furnace is c osed by the usual grate 8.

The furnace proper is surrounded by the usual water-legs '9, and 10' 10 represent the boiler-fines, leading'tcthe front end of the boiler.

It is not our intention to confine our invention to walls or arches of special form or to any-special manner of providing a restricted throat in the furnace'and supplying downweirdly-directed currents or sheets or air in proximity thereto. We, however, prefer to employ front and rear arches erected in the front and back portions of the furnace and somewhat resembling the arches illustrated in the aforesaid patent. Each arch contains one or more air-heating passages, which terminate in cavities .or openings in the under side of the arch and near the inner end thereof. These openings or cavities extend entirely across the furnace, and the air admitted therethrou h is therefore. evenly distributed across the urnace and by reason of the form of the inner walls of said cavities directed downwardly in such manner that the aircurrents from the two arches will converge or meet at a point beneath the throat of the furnace and upon or'soniewhat above the fuel on the grate. We prefer to make our arches of refractory material formed into suitable shapes or bricks. The rear arch is usually composed of two pairs of bricks 11 11 and i2 The bricks are of greater width than length and together bridge the top of the firebox. They are supported upon studs 13 on the side walls of the fire-box and are arched against one another, the meeting joint 14 being strengthened by a tongue and groove 15. Each brick 11 is provided with one or more air-passages 16,-to which air is supplied from tubes, thirnbles, or hollow stay bolts 17, extending through the rear water-leg of the boiler. The inner pair of terminal bricks 12 12 of the rear arch possess the same cross-sectional curve as the pair 11 11, but instead of having tubular passages 16 are provided with cavities or grooves 18 in their under sides. It will be noted that the ends of these bricks are strencthened by ribs or webs 12. The tops of t e cavities -18 communicate withthe passages 16, and the inner walls 19 of the cavitiesare downwardly inclined at a slight angle to the vertical to deflect the air entering through channels in a downward direction upon or toward the fuel on the grate. 13 represents steps or lugs on the sidewalls oi the furnace for preventing longitudinal movement or displacement of the rear arch.

The front arch of the furnace is composed of a air of end bricks 20 20, substantially identical with the, bricks .12 12 of the rear arch, having the same cavities 21 and corresponding deflector surfaces or walls 22. The lower bricks 23 of the front arch are identical or substantially identical with the bricks 11 11, thesarne having like 'air passages 23, which communicate one with the other in abutting bricks. The bottom pair of bricks the grate is increased.

23" are slightly different in shape, the curve thereof being finally merged into a straight line 24 and certain of the ducts 23 being re stricted in size toward the lower end. The thimbles or tubes 25 in the front water-leg of the boiler communicate with the passages23 and the air under the impetus of external pressure asses upwardly therein to be discharged ownwardly from the deflector-sure faces with such velocity as to converge with the streams or currents from the rear arch. The lower front face of the bottom brick of the front arch presents the appearanceshown in Fig. 3, and by thus relatively depressing the lower end of the arch at the middle we are able to avoid closing any of the boilerfines and also to have the arch-passages com municate with air-tubes 25, that are directly beneath the bottom of the boiler-shell, thereby providing for an equal distribution ofthe air transversely across the hollow arch. The bricks composing the front arch have tongue or groove oints, as in the case of the rear arch, and in like manner are supported by lugs or angles 13 on the side sheets of the furnace. The bricks being composed of fireclay are refractory and being constantly cooled by. the air flowing in the channels or passages are capable of withstanding the intense heat of the furnace for a long period and in this regard are preferable to the ordinary solid arch-brick. The highest temperature in the furnace is found in the top thereof above the arches, and we prefer. to make the top walls of the archassages thinner than the lower walls in or er that they may be dis roportionately cooled, and hence equally we 1 preserved.

The operation of our invention is as follows: The exhaust-nozzle (not shown) in the front end of the locomotive-boiler causes a heavy draft of air upward through the grate, as required to maintain combustion thereon.

The partial vacuum in the furnace-chamber caused by the exhaust of gases through the boiler-flues results in the inflow of large volumes of air'through the tubes 17 and 25' and the hollow or channeled arches wherewith' they communicate. The bricks composin the arches are heated to a hi h degree, an the air. entering therethroui is perfectly prepared for admixture with the ases evolved om the fuel. Although the mcoming air is intensely hot, it is nevertheless cooler than the surface of the body ofv burning fuel and also cooler than the ascending gases. The rapidly-moving air-currents being deflected by the end bricks of the arches are directed downwardl Furthermore, the air being cooler and eavier than the rising gases falls naturall and part thereof spreads upon the fire. T us the intensity of combustion upon The downward moveor sheets of air from the ment of the currents by the updraft through two arches is resisted fuel on the grate the furnace, andsaid updraft tends to deflect said currents or streams of air, thus causing them to converge beneath the throat of the furnace. In this I manner a complete curved stratum or, as we prefer to call it, an air barrier is created and maintained in and across the upward path of unconsumed fuel products and poor gases. Allof the comustibles are forced to pass through this barrier, and it is obvious that they are enriched with oxygen therefrom, com lete combustion being thereby insured. t is also obvious that the air which is admitted around and below the throat of the furnace, although already hot, will quickly attain a still higher temperature because of its admixture with the fire-box products and gases, and hence the more quickly enters into combination therewith.

It is substantially true that only perfectly enriched or prepared combustibles escape through the {throat of the furnace and that final and complete combustion occurs in the combustion-chamber directly beneath the crown-sheet, as evidenced by the absence of smoke from the stack of the locomotive. It should be noted that the rear arch overhangs the furnace-door, and the effect of said arch and of the aircurrents projected downwardly therefrom is to revent the direct passage of cold air over t e top of the front arch when the furnace-door is opened. Instead the blast of air entering at the door is deflected by the downwardly-moving currents. or sheets of air from the rear arch and is s read over the fire, and the usual sudden epression of temperature in the top of the fire-box, with consequent, failure of combustion, is avoided. A distinct advantage of our invention is that the reduction of vacuum in the furnace secured by the admission of air is sufficient to suppress the strong draft and prevent carrying over of cinders, and the to of the arch and the lower flues of the boiler are no longer found loaded with cinders, as in the past.

It will be obvious that the throat of the furnace may take various shapes and forms and that there are many ways of introducing air and maintaining the described air barrier between the furnace-throat and the burning When the flow of air through the arches is due to reduced 'pressure (vacuum) in the furnace-chamber, the inclined deflectors are needed to change the direction of the currents and cause them to Having thus described our invention, we claim as new'and desire to secure by Letters Patent I 1. A furnace-chamber, having a suitable grate and provided with a fuel-opening and a smoke-outlet, in combination with a. parti tion or arch extending from side to side and or chambers, means for admitting air into said'furnace-chamber from points adjacent to the walls of said opening or throat and for directing the admitted air downwardly from such oints and thereby maintaining abarrier of air across said throat and within said fire-chamber, through which barrier the combustibles must all pass to reach-said 'combustion-chamber, substantially as described.

2. A furnace-chamber having a grate, a fuel-opening and a smoke-outlet, in combination with arches arranged transversely in said chamber and dividing it into fire and combustion chambers, there being a relatively small opening or throat between the adjacent ends or edges of said arches through which substantiall all of the combustibles from the fire-chain er must pass to reach the combustion-chambers and means for projecting streams of hot air toward the grate and thereby maintaining a barrier of hot air across said throat beneath said arches, substantiall as and for the purpose specified.

3. A urnace-chamber having a suitable grate, and provided with a fuel-opening and a smoke-outlet, in combination with an arch or partitionof refractory material, extending from side to side and. from end to end of said chamber and containing an intermediate opening or throat through which substantially all of the combustibles must pass, said arch being provided with downwardly-opening air-passages in its under side adjacent to said throat and said passages bein arranged to direct streams of air across sai throat in both directions to form and maintain a complete barrier of air beneath the same for enrichin the combustibles before the same pass t rough said throat, substantially as described.

4. A fuel-opening and a smoke-outlet, in combination with a refractory arch arranged between said grate and said outlet, and provided witha relatively small throat for the passage of combustibles therebetween, and means'for forcibly projecting streams of hot fresh air downwardly from said arch and completely across said throat to constitute and maintain an air barrier, through which all the com bustibles must pass before entering said throat, substantially as described.

5, A furnace, having a grate, a fuel-openfurnace-chamber having a grate, a

iiig and a smoke-outlet, in combination with an arch of refractory material arranged in said furnace and dividing the same into fire and combustion chambers, and provided with arestricted throat or passage, said arch beingprovided with air-heating ducts and openings adapted to direct currents of air downwardly in opposite directions across said throat, in such manner as to cause said currents to converge within the fire-chamber and form a complete air barrier coextensive with said throat, substantially as described.

6. A furnace-chamber, provided with a grate, a fuel-entrance and an outlet, in combination with arches arranged in said chamber and provided with air-entrance channels, means at the inner ends of'said arches for deflecting'the air admitted therethrough toward said grate and transversely across and beneath the throat between the arches, substantially as described.

7. A furnace having a grate, a fuel-opening and a smoke-outlet, in combination with an arch or partition dividing the furnace into fire and combustion chambers and containing an opening or throat, forming communication between said chambers, and means for heating air and from numerous points, adjacent to said throat, directing the same forcibly vinto said fire-chamber, said means 5 fuel-openingand an outlet, in combination with arches of refractory material, extending transversely of said fu'.nace, there being a throat or opening between said arches and said arches being provided with air passages and deflectors adapted to cause the streams of air to impinge, thus forcibly maintaining a complete hot-air barrier across the furnace beneath said throar, when the furnace is in operation, substantially as described.

9. A furnace-chamber, having a grate, a fuel-opening and an outlet, in combination with arches extending transversely of said chamber and having a throat between them, such arches having longitudinal air-ch nnels and transversely-disposed downward y-inclined air-deflectors adjacent to said throat, adapted toso direct air-currents that the same will converge below the arch and together form a continuous air barrier across and beneath said throat, substantially as and for the purpose specified.

10. A furnace-chamber, having a grate, a fuel-opening and an outlet, in combination with front and rear arches arranged in said chamber, separated b a throat, com osed of refractory bricks, an containing airieating I ing channels channels and also openings for directing converging currents of air into the space beneath said arches, and means for supplying air to the outer ends of the arch-channels, substantially as described.

11. A furnace-chamber, having agrate, a fuel-opening and an outlet, wherein a partial vacuum is maintained by draft through said outlet, and the walls of which chamber are provided with air-admission o enings, in combination with transverse arc es arranged in said chamber, separated by a throat and havcommunicating with said 0 enings, and said arches being provided at t eir inner ends only with rearwardly-inclined deflecting-suifaces ada ted to direct the currents of air against tlie outflowing gases and maintain an air barrier u on the inner side'of said arches, across said t roat.

12. A furnace-chamber, having a grate, a fuel-entrance and an outlet, in combination with su ports upon the walls of said chamber, arc es separated by a throat and composed of curved bricks arched against one another and sustained by said supports and walls, said bricks containing air-heating con-v duits or channels communicating with the external atmosphere, and the inner end bricks of both arches having inclined deflect ing surfaces or walls, adapted to cause the streams of air to converge beneath the arches, substantially as and for the urpose specified.

13. A furnace-chamber, having a grate, a fuel-opening and an outlet, in combination with refractory arches extending from the vertical walls of said furnace toward the 'middle of the fire-chamber and providing a restricted throat, and means at the inner ends of said arches for directing currents of heated air toward the fire and causing the same to converge beneath said throat; whereby an air barrier is maintained across said throat, substantially as and for the purpose specified.

14. A furnace-chamber, having a grate, a fuel-entrance and an outlet, in combination with arches of refractory material, extending from the vertical walls of said chamber toward the middle thereof and providing a restricted throat, deflectors upon the under sides of said arches, said deflectors extending from wall to wallof the furnace and being inclined downwardly and toward said throat, and means for directing rapidly-moving currents of air against said deflectors to maintain the herein-described air barrier beneath'said throat, within the fire-chamber, substantially as described.

15. A furnace-chamber, having a grate, a fuel-entrance and an outlet, in combination with arches of refractory material extending from the front and rear walls of said chamber and providing a restricted throat in a plane substantially parallel with said grate, said arches being provided with air-entrance channels and having downwardly-inclined defleeting-surfaces, for forcibly maintaining a barrier of air beneath said throat, substantially as and for the pur ose specified.

16. A locomotive-boi er furnace, in combination with a hollow inclined air-feeding arch extending from the lower portion of the fluesheet of said fulnace, said arch being curved in cross-section and having the middle ortion of its lower end relatively depresse or straightened to avoid closing the lower flues in said flue-sheet, substantially as described.

17. The cross-sectional curved lower bricks, 23", presenting a curved surface at one edge and a straight surface at the other edge. and provided with openings or channels, substantially as described.

In testimony whereof we have hereunto set our hands, this 3d day of September, D. 1904, in the presence of two witnesses.

EVAN' H. WADE. JOHN NICHOLSON. 

